Allergic Rhinitis: causes and treatment

Allergic rhinitis can be seasonal, typically caused by tree pollen allergy in the spring and grass pollen allergy in the summer, or perennial, with symptoms all year round relating to exposure to house, dust mite, animal dander, moulds and other allergens. The nose works like an air-conditioning unit for the lungs, and cleans, warms, humidifies and filters the air we breathe – trapping pollen and other irritants on the surface of the turbinates – shelves in the nose that also help to regulate airflow. This leads to an early phase response, mediated by the release of histamine, causing sneezing, itching and a runny nose, and a late phase response mediated by other inflammatory chemicals, which causes nasal congestion. In severe cases the turbinates can become so swollen they block the nose completely, causing sleep disturbance and loss of sense of smell. When the turbinates are very swollen you might even be able to see them if you look into the nose and might be mistaken for being polyps.

Diagnosis can be confirmed with allergy tests, but for hayfever, it’s pretty obvious when the symptoms start and skin prick tests are likely not necessary. The first line of treatment for any allergy is avoidance, but that can be very difficult. Shutting the windows in the house and avoiding drying the washing outside can help, but for many people avoidance is impossible. Rinsing the nose with saline, using products such as NeilMed Sinus Rinse or Sterimar reduces the amount of allergen in the nose and can be helpful, but medication will be needed for many.

The British Society of Allergy and Clinical Immunology recommends a stepwise approach for medical treatment. For those with intermittent symptoms, then an over the counter antihistamine tablet can be used but for those with symptoms most days, a nasal steroid spray is recommended. These have the advantage of delivering the medication directly to where it is needed and can reduce the risk of side effects, but do need to be used on a regular basis to be effective and can take up to a couple of weeks before they start to help. There are a number of sprays that are available over the counter; those with fluticasone and mometasone are better than those with beclomethasone (such as beconase) as this has a much higher rate of absorption into the body. Fluticasone and mometasone have very low rates of absorption so are safe for long term use. Don’t be tempted to use decongestant sprays – as although they might give some short-term relief, if used on a regular basis they make the turbinates swell up even more and become difficult to treat.

When the above methods aren’t enough to control symptoms it’s worth seeking medical advice. The next line of treatment is a combined nasal steroid and antihistamine spray, Dymista, which is only available on prescription. It treats both the early and late parts of the allergic reaction and is much more effective than either an antihistamine tablet, plain steroid spray or both used in combination. Unlike plain steroid sprays, it also has the advantage that it can be used as needed, although is more effective with regular use. Your doctor can also make sure that the diagnosis is correct and that there aren’t other issues such as nasal polyps or a deviated septum.

For most patients this will be enough to achieve good control. For seasonal conditions the spray can be stopped when pollen counts fall at the end of the summer. For the small number that have ongoing symptoms, other options such as immunotherapy (a course of treatment that can induce tolerance, that is stop the allergic reaction) or surgery to reduce the size of the turbinates may be required. Turbinate reduction can be performed in the outpatient clinic under a short local anaesthetic in many cases.